Electric-arc-striking mechanism



C. M. LANGFELD.

ELECTRIC ARC STRIKING MECHANISM.

APPLICATION FILED MAY 13, I9I9.

Patented Feb. 28, 1922.

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usual arc lamp construction the negative is UNITED STATES 'PATENTOFFICE.

CLARENCE M. LANG-FEED, OF BALTIMORE, MARYLAND.

ELECTRIG-ARC STRIKING MEGHANISM 1,4omo1.

Application filed May 13,

Specification of Letters Patent.

Patented Feb. 28, 1922.

1919. Serial No. 296,925.

(FILED UNDER. THE ACT 01 MARCH 3, 1883, 22 STAT. L, 325.)

To all whom it ma concern:

Be it known that I, CLARENCE M. LANG- rnnn, a citizen of the UnitedStates, and a resident of Baltimore, in the county of Baltimore andState of Maryland, have invented alty thereon.

My invention relates to electric arc mechanisms for light projectors orsearchlights and has for its object to provide a simple and reliabledevice by means of which the arc'may be struck.

In the 00:]P8I1d111g application of Lyman C, Josephs, r., Serial Number302,313, filed January 5, 1919, there is shown and described an electricarc mechanism in which the negative carbon is adapted to be manuallyoperable towards the positive gar-bin n t e adapted to be normally heldaway from the positive carbon by means of a spring but experience hasdemonstrated, if the operator holds the negative carbon in contact withthe positive carbon too long or draws the are too slowly, the heavy rushof current following the short circuit between the carbons is liabletoblow the circuit breakers in the electrical supply circuit or otherwisedamage thegenerating apparatus.

By my invention, I provide a device in which the arc is automaticallydrawn as soon as the carbons touch, regardless of the manner in which,the are striking rod may be manipulated by the operator, and while Ihave shown my are striking and release device as applied to the arcmechanism shown and described in the above mentioned copending patentapplication, it is to be understood that it may be as well applied toany other form of arc mechanism.

In the accompanying 'drawings;

Fig. is a transverse sectional view of an electric arc mechanismembodying my invention.

Fig. 2 is a sectional view along the line 2-2 of Fig. 1.

Fig. 3 is a detail view of my device after the are is drawn.

Referring to the drawings, the lamp mechanism comprises a hollowcylindrical casing 1 that fits within a suitable breech casting 2 thatextends through a central opening 3 of a mirror 4.

A tube 9 is centrally supported within the casing 1 by means of endplates 10 and 11, preferably composed of insulating material. The plate10 is provided with a socket 12 electrically connected to tube 9 bymeans of conductor 13 and brush 14:. The tube 9 is closed at one end byan annular plate 15 having a central opening 16 to accommodateportion22, the latter having an operating handle 23 and being suitablysupported by a bushing 24. A cylindrical sleeve 25 is located within theportion 21 and is adapted to be moved longitudinally therein by a rod 26extending through portion 22 and provided at its end with a handle 27 Anarc striker rod 28 housed by tube 18 is provided at one end with acarbon holder embodying an externally threaded union 29, and ampple 30threaded thereon and formed with a socket 31 to receive the negativecarbon 32. The hereinabove described are mechanism forms no part of thisinvention, and is referred to for descriptive purposes only.

My are striking and release device comprises a sleeve 33 designed toengage the inner end j of the rod 28 and is centrally formed with atransverse recess 34 within which are pivotally mounted radially actingpawls 35. To permit radial movement of awls 35 rod 28 is tapered as at28*. Normal y pawls 35 project exterior of the sleeve 33 to engagedetents 36 'pivotally mounted in opposing recesses in the sleeve 25 andnormally forced I inwardly into the path of pawls 35 by springs 37.Pawls 35 are maintained in extended position by spring 38 which bearsagainst the inner end of rod 28 and normally postions its taperedportion in advance of the pawls so that they bear upon the unre- E ducedportion of the rod andare thus prevented from moving inward to releasedposition until the rod has been moved inwardly to properly position itstapered portion beneath the inner edges of the pawls.

Having described the structural arrangement of this invention, itsoperation is as follows :Assuming the various parts of the. arcmechanism to be in their normal position as shown in Figure 1, to strikethe arc, handle 27 is pushed inwardly to bring the electrodes intocontact which is accomplished through the instrumentality of sleeve 25,cooperating pawls 35 and 36, sleeve 33 and rod 28, by which he ativeelectrode 32 and operating handle 2 are indirectly connected.

en the movement of the negative is arrested by contact with the positiveelectrode, sleeve 33 continues to move along the rod. 28, compressingspring 39, until pawls 35 reach portion 28 of the rod 28, the taperedconfiguration of which permits depression of awls 35 and releasement ofsleeve .33. under the influence of spring 39, is caused to move rapidlyto the rear until its movement is arrested by the shoulder 20. Thisretrograde movement of sleeve 33 withdraws negative electrode 32 andthus'very efl'ectively strikes the arc. After the arc has been struck,sleeve 25 is returned to its initial position. The negative carbon 32may be then moved longitudinally by handle 23 reviously referred to.

h rom the foregoing, it is apparent that I have provided an are strikingdevice by means of which the carbons are brought together and the areautomatically drawn b a single movement of the operator, thus eiminating the possibility of a prolonged short circuit betweenthe'carbons. While I have shown my invention in a simple and 'pon beingreleased, sleeve 33 preferred form, as applied to a particular aremechanism, it is not so limited but is susceptible of variousmodifications within the scope of the appended claims.

I claim as my lnvention:

1. Tn an electric arc mechanism, the combination with a positive carbonand a negative carbon, a holder for said negative carbon and operatingmeans for effecting longitudinal movement of said negative toward saidpositive carbon, of a release device interposed between said carbonholder and said operating means for automatically drawing an are betweensaid carbons.

2. In an electric arc mechanism, the combination with a positive carbonand a negative carbon, a rod carrying said negative carbon, a sleeveslidably mounted on said rod, an operating rod provided with a sleeveportionsurrounding said first-named sleeve, and a device between saidsleeve portions whereby said negative carbon rod and said operatin rodare adapted to move together in the direction of said positive carbon,of means for permitting relative movement of said rods in adirectionaway from said positive carbon.

3. In an electric arc mechanism the combination with a positive'andnegative electrode including manually operable means for moving thenegative in the plane of the positive electrode until contact of theelectrodes has been effected; of a releasing device in connection withsaid means for automatically reversing the courseof the negativeelectrode concomitant with the determinatlon of its contact makingmovement, to produce an arc.

4. In an electric arc mechanism the combination with a positive andnegative electrode including manually operable means for longitudinallymovin the negative until contact with the positive electrode has beenmade; of a releasing device in connection with said means forautomatically reversing the action of the negative electrode concomitantwith the determination of its contact makin movement to roduce an arc.

C ARENCE M. ANGFELD.

